Some scientists that tried to arrange the list of elements known before Mendeleev include Antoine Lavoisier, Johann Döbereiner, Alexandre Béguyer de Chancourtois, John Newlands, and Julius Lothar Meyer.

Dimitri Mendeleev was so succesful that he is recognized as the most important in such work.

Mendeleev by writing the properties of the elements on cards elaborated by him, and "playing" trying to order them, realized that, some properties regularly (periodically) repeated.

The elements were sorted in increasing atomic weight (which is not the actual order in the periodic table), but when an element did not meet the pattern discovered, he moved it to a position were its properties fitted.

The amazing creativity of Mendeleev led him to leave blanks for what he thought were places that should be occupied by elements yet undiscovered. More amazing is that he was able to predict the properties of some of those elements.

When years after some of the elements were discovered, the genius of Mendeleev was proven because the "new" elements had the properties predicted by him.

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3 years ago

Question 4 How many carbon-carbon triple bonds are present in a molecule of 4,5-diethyloctane?

ivann1987 [24]

Answer:

We will have zero bonds

Explanation:

In this case, we have to start with the structure of 4,5-diethyloctane. This name ends with the suffix "ane" therefore we have an alkane. All the alkanes are made with single bonds between carbons and single bonds between carbon and hydrogen.

The molecule will have a carbon chain of eight carbons and we will have 2 branches, one ethyl on carbon 4 and another ethyl on carbon 5. (see figure 1)

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3 years ago